Intravascular optical coherence tomography (iOCT) is based on near-infrared light system. The light reflects off plaque and other objects within vessels and the signals are processed into a series of axial images (A-scans) at different positions along the artery to generate a two-dimensional dataset (B-scans). These images are created at an extremely fine resolution of 10-15 μm, which has allowed iOCT to be used in many research settings including PAD and coronary artery disease. OCT has been approved for clinical use in the coronary territory by the FDA in May 2010. Since then many centers have been using iOCT in the daily clinical practice. However, it's still not widely in the clinical management of patients with PAD. There is hope that the high resolution capabilities of iOCT may help before and after an intervention to predict outcomes or correct errors in stent deployment.